Field of the Invention
The invention relates to a silicon on insulator (SOI) cell for power components having at least one insulator layer provided in a semiconductor body. A polycrystalline zone doped with a dopant of a first conductivity type is grown on the at least one insulator layer. The invention also relates to a method for producing such an SOI cell.
A semiconductor component controllable by a field effect is described in Published, Non-Prosecuted, German Patent Application DE 41 13 756 A1, in which an insulator layer adjoins a source zone and is disposed between the source zone and the main face opposite the source zone of the semiconductor body. The insulator layer is intended to prevent the undesired activation of parasitic bipolar structures.
From U.S. Pat. No. 5,396,087, an Insulated Gate Bipolar Transistor (IGBT) is known, in which an insulator layer embedded in the semiconductor body is intended to prevent electrical conduction between a base region and the field effect transistor and in particular to prevent an injection of minority charge carriers from the base region into the source of the field effect transistor.
It is accordingly familiar to one skilled in the art that thin insulator layers under a n.sup.+ zone, for instance, can increase the reliability and robustness of MOSFET and IGBT cells. It is also known that sealing off an IGBT cell with an insulator layer in the direction of an n.sup.- -conducting drain zone reduces the voltage drop in the on state, as is also the case for a so-called trench cell.
In general, however, the production of an embedded insulator layer is complicated and expensive and requires complicated process steps such as in the so-called SIMOX process or the direct wafer bonding process.